Before emergence of human intelligence, physical interactions, aided by intrinsic survival and reproduction characteristics driven by instincts, e.g. fight or flight response, were the only tools of survival and reproduction. Such tools fulfil the survival and reproduction needs for nonhuman organisms, but are not enough for human beings, the reason for which is the additional component of their intelligence. This mental property requires additional solutions which can aid survival and reproduction by handling complex interactions intelligent human life produces, especially with the flexibility provided by the capability of making free will decisions. Also, as they need to be customized to suit each human being's changing conditions and environments, which are based on each and every experience they go through and people they interact with throughout their lives, they cannot be pre-programmed. Such solutions require to be handled on a per-case basis, which can be best done by processing experiences interactively.

In order to explain how such solutions are processed in humans interactively, I will first compare how they execute operations with those of non-living interactive information processing systems.